Method I in this standard specifies the determination methods for 20 species of indicator PCBs (including PCB28, PCB52, PCB101, PCB118, PCB138, PCB153 and PCB180) in foods specified in the Global Environmental Monitoring System/Food Planning Part (GEMS/Food). Method II specifies the determination methods of PCB28, PCB52, PCB101, PCB118, PCB138, PCB153 and PCB180 specified in GEMS/Food.
This standard is applicable to the determination of indicator PCBs in animal-based foods (like fish, shellfish, egg, meat and milk) and their products and oil and fat samples.
The quantification limit of each indicator PCBs in this standard is 0.5μg/kg.
Method I Stable Isotope Diluted Gas Chromatography-mass Spectrometry
2. Principle
Adopt stable isotope dilution technology; add 13C12 labeled PCBs in the sample as the quantitative standard; carry out Soxhlet extraction for 18~24h; carry out chromatography purification, separation and concentration for the extracted sample solution with column chromatography, and then add it into the internal recovery standard; adopt gas chromatography - low-resolution gas chromatograph-mass spectrometer, analyze through quadrupole mass spectrum selected ion monitoring (SIM) or ion trap tandem mass spectrum multi-response monitoring (MRM), and then quantify through internal standard method.
Foreword I Introduction II 1. Scope Method I Stable Isotope Diluted Gas Chromatography-mass Spectrometry 2. Principle 3. Reagents and Materials 4. Instruments 5. Sample Preparation 6. Determination 7. Quality Control and Assurance Method II Gas-chromatographic Method 8. Principle 9. Reagents and Materials 10. Instruments 11. Analysis Procedure 12. Determination 13. Precision Appendix A (Normative) Standard Solution for Indicator Polychlorinated Biphenyl Appendix B (Normative) Characteristic Ion and Isotopic Abundance Ratio Appendix C (Informative) PCBs Mass Chromatogram and Mass Spectrogram through GC-MS Determination Appendix D (Informative) Purification Flow Diagram Appendix E (Informative) Accuracy and Precision
